Implicit finite element algorithms for higher-order gradient plasticity theory (INVITED)

Abstract eng:
We propose an implicit time integration Finite Element (FE) algorithm for Gradient Plasticity (GP) theory, involving both energetic and dissipative higher-order contributions. We consider both phenomenological and crystal GP, in which the free energy includes the so-called defect energy, a function of Nye’s dislocation density tensor. By considering many benchmarks (simple shear of a constrained strip, torsion of thin wires, bending of thin foils, micro-indentation), we show that the conceptually most straightforward FE implementation, in which the displacements and the relevant plastic components are employed as nodal degrees of freedom, leads to a very efficient FE algorithm if a proper regularisation of the viscoplastic potential is adopted, the latter in general involving dissipative higher-order terms. The proposed viscoplastic constitutive law can also accurately represent rate-independent behaviour, without losing computational efficiency.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket